Monoazo dye and process of making same.



UNITED STATES PATENT OFFICE.

WILHELM KONIG, OF OHRDRUF, GERMANY, ASSIGNOR IO KARL MERZ, OFFRANKFURT-ON- THE-MAIN, GERMANY.

Specification of Letters Patent.

Patented Ian. 5, 1909.

Application filed July 80, 1908. Serial No. 446,081.

To all whom it ma concern:

Be it known t at I, WILHELM Komo, doctor of philoso hy, chemist, asubject of the Emperor of german residing at Ohrdruf, in the Duchy ofaxe-Coburg-Gotha, have invented new and useful Improvements in theProduction of Monoazo D estuffs Specially Valuable for Preparing BLie-Red Pigment Colors, of which the following is a specification.

In the face of the combinationroducts of other known 2-naphthylamin-su oacids with 2-naphthol-3-carbon acid I have found that thecombination-dyestufi' naphthalene- 8-sulfoacid-2-azo-2-naphthol-3-carbon acid is most valuable for preparingpigment colors in form of their metal salts specially alkaline earthsalts, a fact which never could be foreseen. Remarkably valuable in thisrespect and a characteristic feature of this d estufl is thebariiim-salt giving a clear b ue-red color of great fire and truenesswhereas the barium-salts of all other dyestulis of the 2-naphthlamin-sulfo acids are of dull nuances, of ess trueness and are thereforenot suitable to be used as igrnent colors. Also the calcium-salt of t henew combination-dyestufi gives a clear bordeaux of very bright nuanceand surpasses in its trueness in a high manner the calcium-salt of thecombination-product of 2-naphthylamin-l-sulfo acid with2-naphthol-3-carbon acid which productgives a less clear and brownishdyestufl' and the calcium-salt of the combination-product of2-naphthylamin-B-sulfo acid with 2-na hthol-3-carbon acid which is of'adee er lue but duller whereas the calcium-5a ts of thecombination-products of 2-naphth lamin-6-sulfo acid and 2-nahthylamin-7-su f0 acid are totally discolored.

From thefore oing results that the valuable 'gment-co ors beforedescribed may onl b obtained with a 2-na hthylami-n-8- sul 0 aciddyestuff totally free rom any other 2-naphthylamin-sulfo acid dyestufi'.

The f0 lowing example vnll serve to explain the method of carrying outthe invention:

Example: 22.3 kilos of 2-naphthylamin-S-sulfo acid are diazotized in asuitable manner and the diazo acid obtained in suspension is then runinto a solution of 18.8 kilos of 2-naphthol-3-carbon acid always keptalkaline. The dyestuil then separates as sodium-salt and thissodium-salt may then v be transformed into any other suitable metal-saltwhich may advantageously be em loyed as a pigment-color either by itselfwit out a base or with one of the usual bases. Of couple the process mayalso be carried out in such a manner that in couplin the ,diazotized2-naphthylamin-8-sulfo aci with 2.3-oxynaphthoicacid the d estuif isobtained at once as Barium or ca cium-salt or any other metal-salt Thesodium-salt of the dyestufi' is a red paste or powder soluble in waterto a red solution and soluble in concentrated sulfuric acid to ablue-red solution from which on addition of water the red-brown freeacid of the dyestuif 1s preci itated which re resents in form of its oter metal-salts a-, Ca-, Pb-salts or others) blue-red powders which maybe employed either by themselves without a base or with ne of the usualbases suitable for producing, pigment-colors of great trueness and tota1y insoluble in water; oil and alcohol.

Having thus described my invention, what I claim and desire to secure byLetters Pat ent, is A 1. The herein described process of producin amonoazo-dyestufl specially valu able or preparing blue-red pigmentcolors, consisting in the combination of the diazotized' 2naphthylamin-8-sulfo acid with 2.3- oxynaphthoic acid. F

2. As 'a new article of lmanufacture the dyestufi' obtained by thecombination of the (llflZOtlZBCl Zmaphthylamin-Ssulfo acid2.3-oxynaphthoic acid and representing in form of itssodium atla redpaste or owder soluble in water to-a red solution, so uble inconcentrated sulfuric acid to a blueered solution from which on additionof water one of t is usual bases for the production of pigment colorsdistinguished bfigreat true ness and total insolubility in watei fioiland alcohol.

In testimony whereof I aflix my signature in presence of two witnesses.

WILHELM manic.

Witnesses:

scam LAUTER, Jr., E3. STENGEL.

